The long term objective of this investigation is directed towards elucidating a potential mechanism whereby membrane-enzyme interactions may participate in the control of cell growth and proliferation. A related objective is to develop sensitive probes for detecting differences in the molecular topography of cell surfaces of Epstein-Barr virus, (EBV)-genome free and EBV positive human lymphoid lines. Successful achievement of this latter goal is a prerequisite for subsequent studies directed towards isolation of EBV determined membrane antigens (MA) and may ultimately aid the development of a viral, nucleic acid-free vaccine for EBV and a radioimmunoassay for MA. Since MA may be functionally relevant to the immunological restriction of tumor growth, these objectives have important clinical ramifications. Major emphasis of these studies is focused on the "signal transduction-amplification process" whereby surface events, possibly even cell-to-cell content, may be related to the control of cell division. Proceeding on the hypothesis that the activity of certain cell surface enzymes may be linked functionally to cytoplasmic structures via microtubule-microfilament (MT-MF) proteins, these studies are investigating the potential interrelationship between surface-associated enzymes and MT-MF proteins. Since membrane preparations from human lymphoic cell lines are capable of covalently modifying their surface components, studies are currently in progress to determine the possible functional relevance of this modification as it may relate to: (1) the regulation of lymphoid cell proliferation; (2) EBV-host cell interaction, and (3) the temporal expression of MA.